An electric motor is a type of a machine that converts electric energy into mechanical energy. Electric motors may be configured as an alternating current (AC) or a direct current (DC) type. Electric motors operate through interacting magnetic fields and current-carrying conductors to generate force. Recent technological advances have facilitated development of compact, high-power electric motors for high-volume applications, such as for powering a vehicle, i.e., a hybrid or electric vehicle.
A stator is the stationary part of a rotor system found in electric motors. The stator may either include permanent magnets or electromagnet windings formed from magnet bars or wires. Depending on the configuration of the electric motor, the stator may act as a field magnet for interacting with an armature to generate motion, or it may act as the armature, receiving its influence from moving field coils on the rotor. Stators often use various shims to mechanically separate the magnet bars or wires for durability, and, typically, also use dielectric insulators to isolate magnet bars or wires of dissimilar phases.